In conventional spinning processes for cotton spinning plants and combed yarn spinning plants operating with roving frames, also known as flyer frames, roving bobbins with weights up to about 3 kg are used. These bobbins have had a starting winding height of about 360 mm to about 410 mm (14 inches in the English system to 16 inches in the English system) and a greatest winding diameter of about 140 mm to 180 mm (51/2 inches to 7 inches). These bobbin dimensions have generally been found to be an optimum in the past and have determined the production speed of the roving frame, the way in which the roving bobbins have been handled, the configuration of the creel of the ring-spinning machine and other factors in the processing of yarn to the point that there has been no basic change in these parameters of the roving yarn for many many years.
In recent years, however, machines and systems in the spinning field have undergone improvement and development. To the extent that such improved machines and concepts are utilized for the present invention, reference may be made to publications, especially patents, it being understood that the systems described in such publications or patents are the ones intended to be used for the present invention when a more detailed description has been avoided in favor of a citation of the particular reference.
For example, in terms of roving frames or flyer machines, so-called multi-axial flyers or roving frames have been described in which the machine has been equipped with a variety of independently controllable drives. A four-axis machine is described, for example, in German patent document DE 34 17 779 C2. This machine has independent drives for the flyer, the bobbins, the bobbin rail (i.e. the upwardly and downwardly movable support for the bobbins while they are within the flyers), and the drafting frame. These drives may be separate motors whose individual speeds are independently controllable. With such a system the conventional steplessly adjustable cone transmission which is used to drive the bobbins and the bobbin rail from a common prime mover is eliminated. The multi-axial drive has been described as enabling a simplified construction of the roving frame with the advantage of greater accuracy of control of the working elements, especially in terms of a speed difference between the flyers and the bobbins and the lifting speed of the bobbin rail. This permits a more precise building of the turns on the roving bobbin with a reduction in defects and elimination of slippage of the windings.
In connection with roving frames bobbin replacement mechanisms have also been described which permit the fully-wound, roving bobbins to be automatically removed from the bobbin rail and, for example, suspended from hangers of a suspension carriage train traveling as a rule overhead in the plant. The automatic bobbin-change system eliminates the heavy work which previously had to be performed by an operator in the doffing of the full bobbin from the flyer frame and the suspending of the full bobbin from the suspension carriage train. A suitable bobbin change or bobbin replacement mechanism has been described in German patent document DE 36 30 214 C3.
The suspension carriage systems which have been developed in recent years also include tracks which enable the suspension carriage trains to be introduced into the creels of the ring-spinning machines so that the full roving bobbins can remain suspended from the trains while they are in a creel. Such an arrangement has been shown and described, for example, in German patent document DE 37 09 540 C2.
In other cases automatic bobbin exchange units are used which can remove the full roving bobbins from the suspension carriage train and attach them to the hangers of the creel of the ring-spinning machine. Such an arrangement is described, for example, in German patent document DE 37 34 275 A1. In either case the muscle work required earlier by service personnel in the handling of overhead full roving bobbins is eliminated.
While all three of these developments have been available for a number of years, we are not aware that they have ever been combined before so as to enable the dimensions and weight of the bobbins which are handled to be substantially increased and hence the productivity of the system to be significantly increased.